See these from SRAC

http://srac.tamu.edu/index.cfm?catid=13

Water quality

Selection of a site for red drum

production must be based on the

knowledge that adults can survive in

either freshwater or saltwater. The

larvae require salinities of 25 to 35

ppt for at least their first 30 days. In

addition, red drum require water

with a calcium content greater than

100 ppm and a chloride content

greater than 150 ppm for good survival.

For optimum growth the calcium

content should be more than

150 ppm and the chloride content

greater than 1,000 ppm.



Temperature

Red drum cannot tolerate extended

periods of time when water temperatures

temperatures

are below 40�F. Selection of a

site must consider the normal minimum

(not average) low temperature

in an area. Heated water can be

used but it is not readily available in

most areas. Red drum will tolerate

low salinity water, but survival is

reduced in water below 50�F and

lower than 5 ppt salinity. Air

temperature directly affects water

temperature; therefore, if yearround

water temperature data are

not available, check the air temperature

data from the closest reporting

station. If available use the frequency

and duration of freezing temperatures

rather than average daily

temperatures. A few consecutive

days of freezing temperatures can

destroy an entire crop of red drum

in unheated outdoor raceways or ponds.